This study aims to determine the prevalence and clinicopathologic characteristics of patients with endometrial serous and clear cell carcinoma in a tertiary referral center in the Philippines. It will identify and review patients’ clinical profiles, tumor characteristics, management approaches, and determine their associations with treatment outcomes.

This 5-year retrospective cross-sectional study reviewed all women diagnosed with serous and clear cell endometrial carcinoma in a tertiary cancer referral center in the Philippines from January 2018 to December 2022. Statistical analysis with univariate and multivariate analysis was done to determine association of clinical and tumor characteristics with treatment outcomes. Odds ratios and f-test were used to determine significant relationships among variables.

One thousand new endometrial cancer cases were identified during the study. Prevalence for serous carcinoma was 6.8% and 3.5% for clear cell carcinoma. Both were commonly encountered in the postmenopausal age, with a mean age of presentation of 62 years. Surgery was performed through open surgery for all cases, and included lymphadenectomy and omentectomy. Adjuvant systemic chemotherapy alone was given for 48.5% of serous cases, and in combination with radiotherapy in 42.86% of clear cell cases. Lymphovascular space invasion was significantly associated with treatment outcome for serous carcinoma while depth of invasion was significant for clear cell carcinoma. Among the cases, 41.8 % of serous and 28.57% of clear cell had extrapelvic metastasis, with omentum and lymph nodes as the the more common sites. Adjuvant chemotherapy and multimodal approach of radiation with external pelvic radiotherapy and vaginal brachytherapy impacted treatment outcome.

High-grade endometrial histologies are less common and tend to have more aggressive and less predictable behavior. Surgery is the mainstay of treatment followed by combination adjuvant therapy. Our study shows that the omentum is a common site of extrapelvic metastasis. This supports the need for omentectomy for both serous and clear cell cases, even in early stages. Prognosis tends to be less favorable and recurrences and distant metastasis may occur even for earlier stages. Thus, it is important to identify any clinical factors that may aid in better counseling and giving tailored management for these patients.